To be fair WTCC was never really as good as the original ETCC was when it started.
Eurosport boxed it, p[packaged it and tried to sell for money to any venue that would pay for it, and most decent ones stopped paying for it as it did not bring in a crowd at all.
The best eras were sort of 07 ish, then the early diesel era.
Citroen totally destroyed the series spending a year testing a new regs car while everyone was using other ones, and spending millions more than anyone else.
Than ran off back of to rallying after winning a series that got them no plaudits at all coz no-one else was bothered about it after they came in